Biphenotypic siononasal sarcoma with acute exacerbation: A case report

Background: Biphenotypic sinonasal sarcoma (BSNS) is a rare sarcoma with neural and myogenic pathological features. Histopathologically, BSNS has been regarded as a low-malignant tumor with favorable prognosis. Herein, we report a case of BSNS with a seemingly high-grade malignancy and an extremely acute exacerbation. Case description: A 64-year-old woman was diagnosed with BSNS and underwent surgical extraction of a tumor twice. Two months later after the second operation, recurrence occurred, with intracranial tumor extension as well as infiltrations around the carotid artery. Two cycles of chemotherapy with doxorubicin and ifosfamide were administered, which significantly reduced the tumor volume. Subsequently, a treatment with oral pazopanib was administered. No tumor progression was observed in the next 2 and a half months, followed by local progression. Discussion: Our case seems to be entirely different from those described in previous reports on BSNS and should be regarded clinically as an extremely high malignant tumor. This high malignancy involved the high proliferative activity and invasiveness of critical organs such as in the intracranial area. AI therapy consisted of a regimen with doxorubicin and ifosfamide showed anti-tumor effects, as well as a temporary inhibition of tumor progression was achieved with pazopanib. Conclusion: AI therapy and pazopanib might be considered as a potential postoperative adjuvant therapy and second-line therapy for severe BSNS.